Disconnected UI incorrectly shown for Gemini in certain case

[LaurenWags]

Description

If a user tries to connect 2 custodial wallets (in this case Gemini) to the same payment ID, instead of seeing "Verify wallet" UI after attempting to connect the second account the "Disconnected" UI is shown. This works in the Uphold case but not in the Gemini case.

Additionally, there is another problem where a notification should be shown on the panel per #16468 for this case. This is working in the Uphold case, but not Gemini. This will be logged separately.

Steps to Reproduce

1. Clean install, staging env. Enable Gemini in flags and restart.
2. Enable Rewards, link KYC'd Gemini wallet
3. Manually disconnect from Gemini (from wallet panel)
4. Confirm you are returned to pre-link state (UI, no balance, etc)
5. Link a second (different) KYC'd Gemini wallet
6. Logs show 403 error like below:

[ REQUEST ]
> URL: https://grant.rewards.bravesoftware.com/v3/wallet/gemini/9......b/claim
> Method: POST
> Content: {"linking_info":"eyJ0......
[98738:259:0819/115838.142307:VERBOSE6:logging_util.cc(136)] 
[ RESPONSE - OnRequest ]
> Url: https://grant.rewards.bravesoftware.com/v3/wallet/gemini/9.......b/claim
> Result: Failure
> HTTP Code: 403
> Body: {"message":"error linking wallet: unable to link wallets: unable to match wallets: wallets do not match","code":403}

--> UI shows "Disconnected" and a balance (balance part will likely be fixed with #17474)
--> no error modal like the one requested in #16468 is shown (logged as #17569 )

Actual result:

UI shows below

Example	Example

Expected result:

Should show "verify wallet" not "disconnected". Balance showing is likely fixed by another issue.

Reproduces how often:

easily

Brave version (brave://version info)

Brave 1.29.64 Chromium: 92.0.4515.159 (Official Build) beta (x86_64)
Revision 0185b8a19c88c5dfd3e6c0da6686d799e9bc3b52-refs/branch-heads/4515@{#2052}
OS macOS Version 11.5.1 (Build 20G80)

Version/Channel Information:

• Can you reproduce this issue with the current release? n/a
• Can you reproduce this issue with the beta channel? yes
• Can you reproduce this issue with the nightly channel? Balance does not display in this case using Nightly, but the incorrect "Disconnected" status is still shown. using 1.30.34.

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields?
• Does the issue resolve itself when disabling Brave Rewards?
• Is the issue reproducible on the latest version of Chrome?

Miscellaneous Information:

cc @Miyayes @jumde

[LaurenWags]

Verified using:

Brave	1.29.70 Chromium: 92.0.4515.159 (Official Build) beta (x86_64)
Revision	0185b8a19c88c5dfd3e6c0da6686d799e9bc3b52-refs/branch-heads/4515@{#2052}
OS	macOS Version 11.5.2 (Build 20G95)

Verified test plan from brave/brave-core#9817 (comment)
Verified STR from description

Confirmed an error message is shown. Note, error text is generic and not descriptive of the problem. To be addressed with #17661. This does not reproduce for Uphold but does reproduce for bitFlyer (#17592):

Confirmed UI returns to pre-link state. It does not show "Disconnected" UI or a balance. "Verify wallet" is shown and no balance is displayed:

Example	Example